Explosive well tool firing head

Abstract

A firing head embodiment of the invention confines a connected capacitance cartridge, explosive detonator, and wireline connection switch within an independent, cylindrical housing tube that is environmentally capped at both ends by threaded closures for secure transport to a well site.

The invention claimed is: 
     
       1. A method of arming an explosive well tool comprising the steps of:
 providing an axially elongated firing head housing having first mechanical assembly means at one end thereof: 
 securing an explosive detonator means to said housing to project axially beyond said one end of said housing; 
 enclosing said detonator means by a detonator cover of sufficient structural integrity to confine a detonation of said detonator means; 
 securing said detonator cover to said housing by said first assembly means: 
 providing operating signal contact means at an opposite axial end of said housing; 
 providing a capacitive firing cartridge connected electrically between said signal contacts and said detonator means; 
 delivering said housing to a well site with said firing cartridge connected to said signal contact means and to said detonator means and said detonator cover enclosing said detonator means and secured to said first assembly means; 
 at said well site, with said detonator cover secured to said first assembly means, securing signal carrier means to said opposite end of said housing for signal continuity with said signal contact means; 
 removing said detonator cover means from said housing; and, 
 connecting an explosive well tool to said housing at said one end by said first assembly means. 
 
     
     
       2. A method of arming an explosive well tool as described by  claim 1  wherein said explosive well tool connection comprises the step of connecting a shaped charge tubing cutter. 
     
     
       3. A method of arming an explosive well tool as described by  claim 1  further comprising the steps of:
 providing environmental cover means for said signal contact means; 
 providing said housing with second mechanical assembly means proximate of said housing opposite end; 
 securing said environmental cover to said housing by said second assembly means; 
 delivering said housing to a well site with said environmental cover secured to said second assembly means; 
 removing said environmental cover from said housing; and 
 connecting said signal carrier means with said second assembly means. 
 
     
     
       4. A method of arming an explosive well tool as described by  claim 3  wherein said second assembly means is provided with screw threads. 
     
     
       5. A method of arming an explosive well tool as described by  claim 1  wherein said first assembly means is provided with screw threads.